Fourth-seeded Julia Goerges of Germany was eliminated in the first round of Monterrey Open on Tuesday after a 6-1, 7-5 loss to Ksenia Pervak of Russia.
Other seeded players had better results in the hard-court tournament.
Second-seeded Anastasia Pavlyuchenkova of Russia had a 6-3, 6-7 (5), 6-4 win over Eleni Daniilidou of Greece in a night match.
No. 5 Anastasija Sevastova of Latvia defeated Laura Pous-Tio of Spain 6-2, 6-4, and No. 6 Sara Errani of Italy had a 6-2, 6-4 win over Johanna Larsson of Sweden.
Top-seeded Jelena Jankovic was to play on Wednesday.